acalculator

What is the pressure?

Type a force and the area it presses on to get the pressure, or solve for the force or the area. The pressure calculator works in newtons, pounds-force, square meters and square inches, and shows pascals, psi, bar and atmospheres.

Your numbers

Units
Find
Answer
P = 2000 Pa (0.290075 psi)

The answer is P = 2000 Pa (0.290075 psi).

Pressure (Pa)
2,000
Pressure (kPa)
2
Pressure (psi)
0.290075
Pressure (bar)
0.02
Pressure (atm)
0.0197385
Force (N)
500
Force (lbf)
112.404
Area (m²)
0.25
Area (in²)
387.501

Answer: P = 2000 Pa (0.290075 psi). The answer is P = 2000 Pa (0.290075 psi).

How to calculate

Computes pressure from force and area (P = F ÷ A), or the force from the pressure and area, or the area from the force and pressure, in pascals, kPa, bar, psi and atmospheres.

Example with the default inputs (Find Pressure, Force 112.404471549855 lbf, Area 387.50077500155 in²): The answer is P = 2000 Pa (0.290075 psi).

Method: P = F ÷ A; F = P × A; A = F ÷ P.

  • The force presses straight onto the surface (perpendicular to it) and is spread evenly over the area.
  • Exact unit sizes: 1 lbf = 4.4482216152605 N; 1 in² = 0.00064516 m²; 1 psi = 6,894.757293168361… Pa; 1 bar = 100,000 Pa; 1 atm = 101,325 Pa; 1 mmHg = 133.322387415 Pa.

Machine-readable copies: Markdown, JSON.

Worked examples

Each example is checked against the calculator on every build.

  1. Find Pressure, Force 112.4 lbf, Area 387.5 in² gives Pressure (Pa) 2,000, Pressure (kPa) 2, Answer P = 2000 Pa (0.290075 psi).Source: OpenStax, University Physics Volume 1, §14.1 Fluids, Density, and Pressure (p = F ÷ A), https://openstax.org/books/university-physics-volume-1/pages/14-1-fluids-density-and-pressure
  2. Find Pressure, Force 1 lbf, Area 1 in² gives Pressure (psi) 1, Pressure (Pa) 6,894.757293.Source: NIST SP 811, Appendix B.8 (1 lbf = 4.4482216152605 N; 1 in = 0.0254 m; 1 atm = 101,325 Pa; 1 bar = 100,000 Pa), https://www.nist.gov/pml/special-publication-811
  3. Find Force, Pressure 14.7 psi, Area 1,550 in² gives Force (N) 101,325, Pressure (atm) 1.Source: OpenStax, University Physics Volume 1, §14.1 Fluids, Density, and Pressure (p = F ÷ A), https://openstax.org/books/university-physics-volume-1/pages/14-1-fluids-density-and-pressure; NIST SP 811, Appendix B.8 (1 lbf = 4.4482216152605 N; 1 in = 0.0254 m; 1 atm = 101,325 Pa; 1 bar = 100,000 Pa), https://www.nist.gov/pml/special-publication-811
  4. Find Area, Force 157.4 lbf, Pressure 29.01 psi gives Area (m²) 0.0035, Answer A = 0.0035 m² (5.42501 in²).Source: OpenStax, University Physics Volume 1, §14.1 Fluids, Density, and Pressure (p = F ÷ A), https://openstax.org/books/university-physics-volume-1/pages/14-1-fluids-density-and-pressure

How it works

Pick what to find, then type the other two:

  • Pressure: P = F ÷ A
  • Force: F = P × A
  • Area: A = F ÷ P

The page works in newtons, square meters and pascals, then shows the pressure in Pa, kPa (Pa ÷ 1,000), psi (Pa ÷ 6,894.757293168361…), bar (Pa ÷ 100,000) and atm (Pa ÷ 101,325), the force in N and lbf (N ÷ 4.4482216152605), and the area in m² and in² (m² ÷ 0.00064516).

Unit sizes: 1 kN = 1,000 N; 1 lbf = 4.4482216152605 N; 1 kgf = 9.80665 N. 1 cm² = 10⁻⁴ m²; 1 mm² = 10⁻⁶ m²; 1 in² = 0.00064516 m²; 1 ft² = 0.09290304 m². 1 kPa = 1,000 Pa; 1 MPa = 10⁶ Pa; 1 bar = 100,000 Pa; 1 psi = 4.4482216152605 ÷ 0.00064516 Pa; 1 atm = 101,325 Pa; 1 mmHg = 13.5951 × 9.80665 = 133.322387415 Pa.

Exact arithmetic. Each value is read as the exact decimal you typed, in its unit, and every unit size is exact, so each result is an exact fraction until it is rounded for display.

Output format. The answer line shows 6 significant figures with no thousands separators: P = 2000 Pa (0.290075 psi), F = … N (… lbf) or A = … m² (… in²). Every value row shows 6 significant figures; values of 10¹⁵ or more, or below 10⁻⁶, show in scientific form (in the answer line too).

When there is no answer.

  • A solved force over 10¹⁵ N, or a solved area over 10¹² m².
  • A value so small that it is below the smallest number a computer can hold.

Assumptions

  • The force is perpendicular to the surface and spread evenly over it.
  • Force 10⁻⁹ to 10¹⁵ N; area 10⁻¹² to 10¹² m²; pressure 10⁻⁹ to 10¹⁵ Pa.

Worked examples by hand

500 N over 0.25 m². P = 500 ÷ 0.25 = 2,000 Pa = 2 kPa = 2,000 ÷ 6,894.757 = 0.290075 psi.

1 lbf on 1 in². P = 4.4482216152605 ÷ 0.00064516 = 6,894.76 Pa = 1 psi.

One atmosphere on 1 m². F = 101,325 × 1 = 101,325 N.

700 N at 200,000 Pa. A = 700 ÷ 200,000 = 0.0035 m² = 0.0035 ÷ 0.00064516 = 5.42501 in².

Other questions people ask

What is the formula for pressure?

Pressure is force divided by area: P = F ÷ A. A force of 500 N spread over 0.25 m² gives 500 ÷ 0.25 = 2,000 Pa (2 kPa).

What is a pascal?

One pascal (Pa) is one newton per square meter. It is a small unit: air pressure at sea level is 101,325 Pa, so kPa, bar and psi are more common in practice.

How do I convert psi to pascals?

1 psi is one pound-force on one square inch: 4.4482216152605 N ÷ 0.00064516 m² = 6,894.757 Pa. So 30 psi is about 206.8 kPa.

How do I find the force from pressure?

Multiply the pressure by the area: F = P × A. One atmosphere (101,325 Pa) on 1 m² pushes with 101,325 N, about 22,779 lbf.

Why does a sharp knife cut better?

The same force on a smaller area gives a higher pressure. Halve the area and the pressure doubles.

What is the difference between bar and atm?

1 bar is exactly 100,000 Pa. 1 standard atmosphere is 101,325 Pa, about 1.013 bar.